Automatically calculate attack and damage bonuses

[rg-wood]

Automatically calculate attack and damage bonuses from ability score modifiers.

For example, if a Strength +3 monster has an attack defined without attack bonus or damage as follows:

                  {
                    "name": "Dagger",
                    "type": "melee-or-ranged-attack",
                    "reach": "5ft.",
                    "range": "20/60 ft.",
                    "target": "one target",
                    "damageDie": "2d4",
                    "damageType": "slashing"
                  }

We end up with actual attack bonus of +5 and a damage of 2d4+4.